GRAFT COPOLYMERS BY OXONIUM POLYMERIZATION .6. REACTIONS OF MODEL ORGANIC HALIDES WITH SILVER AND OTHER SALTS

In a previous report, the authors described a new efficient synthesis for the preparation of polytetrahydrofuran (PTHF) graft copolymers by adding silver triflate to a solution of macrohalides (e. g. , PVC) in tetrahydrofuran (THF). In this short communication, they report the results of preliminary investigations of the interaction of a variety of inorganic salts, small organic halides, and THF. These studies were carried out for the combined purposes of understanding the initiation mechanism and of determining the specificity of the silver triflate for grafting reactions. Extensive experimental data are tabulated and evaluated. It is shown that the allyl and tertiary halogens in the halogenated polymers are the reactive sites. It is demonstrated that allyl halides, benzyl halides, and t-butyl halides are promising for generating oxonium ions from THF by reaction with silver salts, and are thus promising for the preparation of graft copolymers. Acyl halides are also suitable. Of the cations examined so far, silver is the most versatile.